1. Field of the Invention
The present invention relates generally to explosive device simulation systems for use in military training exercises and, more particularly, for methods and apparatus for simulating the effects of indirect and/or non-directional weapon fire in tactical electronic combat training environments.
2. Description of the Prior Art
The introduction of the MILES system has changed the way the military trains for combat. The word MILES is an acronym for "Multiple Integrated Laser Engagement System." The MILES system has been fielded with armies of many nations around the world and has become the international standard against which all other Tactical Engagement Simulation (TES) systems are measured. For the U.S. Army and Marine Corps, MILES is the keystone for their opposing force, free-play TES Program. It is highly valued in its ability to accurately assess battle outcomes and to teach soldiers the skills required to survive in combat and destroy the enemy.
Briefly, the MILES system uses laser bullets in combination with laser sensitive detectors to simulate the lethality and realism of the modern tactical battlefield. Eye-safe Gallium Arsenide (GaAs) laser transmitters, capable of shooting pulses of coded infrared energy, simulate the effects of live ammunition. The transmitters are easily attached to and removed from all hand-carried and vehicle-mounted direct-fire weapons. Detectors located on opposing force troops, vehicles, and other point targets receive the coded laser pulses. MILES decoders then determine whether the target was hit by a weapon that could cause damage in a hierarchy of weapons effects and whether the laser bullet was accurate enough to cause a casualty. The target vehicles or troops are made instantly aware of the accuracy of the simulated shot by means of audio alarms and visual displays, which can indicate either a hit or a near miss.
In use, the coded laser (infrared) energy is received by silicon detectors located on the point targets. In the case of ground troops, the detectors are installed on webbing material that resembles the standard-issue load-carrying lift harness. Additional detectors are attached to a web band that fits on standard-issue helmets. For vehicles, the detectors are mounted on belts that easily attach to the front, rear, and sides. The detectors provide 360-degree coverage in azimuth and sufficient elevation coverage to receive the infrared energy during an air attack. The arriving pulses are sensed by detectors, amplified, and then compared to a threshold level. If the pulses exceed the threshold, a single bit is registered in the MILES detection logic. Once a proper arrangement of bits exists, corresponding to a valid code for a particular weapon, the decoder decides whether the code is a near miss or a hit. If a hit is registered, a hierarchy decision is then made to determine if this type of weapon can indeed cause a kill against this particular target and, if so, what the probability of kill might be.
With MILES, commanders at all levels can conduct opposing force free-play tactical engagement simulation training exercises that duplicate the lethality and stress of actual combat. However, existing MILES training systems have been largely limited to simulating combat situations involving direct, line-of-sight weapons fire.
In presently existing military training environments, indirect fire from mortars, artillery, and the like non-directional weapons are often simulated by physically placing devices in the battle area. These devices at the pre-planned time for artillery/mortar fire are hand-placed into the area and referees decide which soldiers or vehicles in the battle are eliminated. More advanced systems, such as the one described in U.S. Pat. No. 4,744,761 to Doerfel et al., propose to inject timed RF signals into the battle zone, so soldiers or vehicles exposed to the RF signal will be "eliminated" through activation of their MILES II system. The MILES II system differs from the MILES system in that it also interacts with RF signals. Though both approaches provide means to train, both lack realism in their execution. In one case, the war game participants see a flash, in others they sense the interaction of an RF signal with their MILES system. As will be later seen, the teachings of the present invention will provide a flash (explosion) upon command and an interactive means with the MILES-type harness found on soldiers or vehicles.
Other systems for injecting increased degrees of realism into simulated weapon fire exercises are disclosed in U.S. Pat. Nos. 5,207,579 to Campagnuolo and 5,199,874 to Campagnuolo et al.--both assigned to the same assignee as the present invention, the U.S. Government. In the '579 patent the effects of an antipersonnel mine are simulated by having a MILES system located on a target respond to the acoustic output of the mine upon simulated detonation initiated by conventional physical contact/trip-wire means. In the '874 patent, an acoustic receiver for use with a MILES-type tactical simulation system is described that incorporates preexisting anti-tampering circuitry as part of the acoustic detection technique.
Up to the present time, it has been difficult to include the effects of a MILES grenade into realistic tactical simulations since the grenade effects are non-directional and hence would require many laser emitters to ensure that at least one beam would be pointed to the target. Similar problems are encountered with the other types of non-directional weapons. Because of these difficulties, no truly suitable system to simulate non-directional or indirect weapon fire are presently available.